Efficient removal of oil pollutant via simultaneous adsorption and photocatalysis using La–N–TiO2–cellulose/SiO2 difunctional aerogel composite

Nano-TiO 2 photocatalysts doped with La–N(La–N–TiO 2 ) were prepared by solgel method. The La–N–TiO 2 was loaded on the cellulose/SiO 2 composite aerogel (La–N–TiO 2 –CSA). La–N–TiO 2 –CSA had both oil absorption and oil degradation functions under the sun. The static state water contact angle is up to 148° close to superhydrophobic surface. An apparent decomposition rate of oil is 92%, which is much higher than 26% of pure TiO 2 . Under the visible light irradiation, the photocurrent density has increased by 50%. Characterization results show that LaONO 3 was uniformly distributed in TiO 2 crystal. Compared with pure TiO 2 , the UV–Vis DRS data showed the absorption band of La–N–TiO 2 had extended to 441 nm. The La increased the valence band position and N lowered the conduction band position, which reduced the band gap of TiO 2 from 3.59 to 2.81 eV. The formation of LaONO 3 reduced carrier transfer resistance, and the migration rate and electron–hole separation efficiency were improved. The possible oil decomposition pathways were proposed. Graphic abstract